1. Field of the Invention
The invention relates to a vehicle seat with a built-in blower.
2. Description of Related Art
A vehicle seat of the aforementioned type is described in Japanese Patent Application Publication No. 2000-70071 (JP 2000-70071 A). The vehicle seat includes a seat cushion, a seatback, and a blower. The blower includes a centrifugal blower mechanism that blows air in the centrifugal direction while sucking in external air from the axial direction of the blower. The seatback has a cushion member that defines the outer shape of the seatback, and fabric upholstery. A flow passage is formed in the cushion member.
The flow passage is formed of grooves and an introducing passage. The grooves are recesses formed in a seating-side portion of the cushion member, and arranged in a branched structure. The introducing passage is formed inside the cushion member, and provides communication between the blower and the grooves. According to the conventional technique, the blower is provided inside the seatback and the seating-side portion of the cushion member is covered with a cover. The cover is a porous flat member having appropriate air permeability. Then, the cushion member and the blower are covered with the upholstery. After that, the air blown out of the blower is supplied to an occupant through the flow passage (introducing passage, grooves) of the cushion member and the cover.
In the vehicle seat of this type, it is desirable that the amount of air supplied from the center of the seatback and the amount of air supplied from the side portions of the seatback be adjusted appropriately based on the manner in which the occupant is seated in the vehicle seat. For example, when the occupant is seated in the vehicle seat without contacting the seatback, preferably, the air is supplied to the occupant mainly from the center of the seatback. On the other hand, when the occupant is leaning against the seatback, that is, when the occupant's body is in contact with the center of the seatback, preferably, the air is supplied to the occupant from the side portions of the seatback, for example, from the portions of the seatback on the sides of the lower back of the occupant. However, according to the conventional technique, the air that passes through the grooves is uniformly blown out of the porous cover. Therefore, the configuration according to the conventional technique is unsuitable for causing a difference between the amount of air supplied from the center of the seatback and the amount of air supplied from the side portions of the seatback. In other words, there is still room for improvement in the efficiency in supplying the air to the occupant.